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The Characteristics of Spatio-temporal Distribution on Environmental Factors After Construction of Artificial Structure in the Nakdong River Estuary

인공시설물 건설 이후 낙동강 하구 환경인자의 시·공간적분포특성

  • 윤상철 (국립수산과학원 기후변화연구과) ;
  • 윤석현 (국립수산과학원 기후변화연구과) ;
  • 서영상 (국립수산과학원 기후변화연구과)
  • Received : 2016.08.24
  • Accepted : 2017.02.20
  • Published : 2017.02.25

Abstract

Nakdong River Estuary is affected by the dam, barrage construction and dredge and reclaim worked artificially. So, we have studied the area input both freshwater and sea water to understand marine environment of Nakdong River estuary related to the effect of artificial work from 2013 to 2015. As a result, The discharge flow to the estuary remarkably decreased before barrage construction and the average of salinity at the estuary increased. So, the brackish water zone reduced under the influence of decreased discharge flow. The major sources of nitrate and silicate were freshwater, phosphate supplied from bottom and the open sea water. The concentration of phosphate and dissolved oxygen (DO) decreased remarkably in spring and summer. we investigated that phosphate in freshwater was removed under the influence of the estuary dam and phosphate in sea water was removed under the influence of phytoplankton. The low concentration of DO was due to decomposition of the organic compound by microorganism after phytoplankton blooms. Generally, the concentrations of chlorophyll-a in summer was higher than spring and fall. Therefore, the change of ecosystem in Nakdong river estuary was due to decrease of freshwater influx, the other change is facing because of the barrage.

낙동강 하구는 최근 하구둑, 보 등의 인공시설물 건설과 매립 및 준설 등 인위적인 활동에 많은 영향을 받고 있다. 따라서 이러한 인위적 영향에 대한 낙동강 하구의 해양환경 변화를 확인하고자 2013년부터 2015년까지 하구로 유입되는 담수를 비롯하여 해수역을 중심으로 연구하였다. 그 결과 하구로 유입되는 방류량은 보 건설전에 비해 현저히 감소하였고, 평균 염분은 증가하여 기수역이 감소한 것을 확인하였다. 질산염과 규산염의 주요 공급원은 유입되는 담수로 나타났으며 인산염은 저층과 외해에서 공급되었다. 인산염과 용존산소의 농도는 춘계와 하계에 급격히 감소하는 양상을 나타냈다. 담수의 인산염은 하구둑에 의한 영향으로 제거되었고, 해수의 인산염은 식물플랑크톤에 의해 제거 되는 것을 확인하였다. 낮은 용존산소 농도는 식물플랑크톤의 대번성 이후 미생물에 의해 분해되면서 저층에서 소모되어 나타난 결과로 판단된다. 일반적으로 춘계와 추계에 대번성하는 식물플랑크톤의 일반적인 특성에 비해 낙동강 하구에서는 하계에 높은 경향을 보였다. 따라서 낙동강 하구의 생태계 변화는 유입되는 담수의 유량 감소에 의한 것으로 보에 의해 또 다른 환경변화에 직면해 있다.

Keywords

References

  1. Chen, C.-C., Gong, G.-C. and Shiah, F.-K., 2007, "Hypoxia in the East China Sea: One of the largest coastal low-oxygen areas in the world", Mar. Environ. Res., Vol. 64, 399-408. https://doi.org/10.1016/j.marenvres.2007.01.007
  2. Chen, C.T.A., 2000, "The Three Gorges Dam: Reducing the upwelling and thus productivity in the East China Sea", Geophysical Res. Lett., Vol. 27, No. 3, 381-383. https://doi.org/10.1029/1999GL002373
  3. Cho, K.-J. and Shin, J.-G., 1995, "Distribution and variation of chlorophyll-a from midstream to downstream of the Naktong river", Kor. J. Lim., Vol. 28, No. 4, 421-426.
  4. Cho, K.-J. and Shin, J.-G., 1997, "Dynamics of inorganic N.P nutrient from midstream to downstream of the Naktong river", Kor. J. Lim., Vol. 30, No. 2, 85-95.
  5. Cho, K.-J. and Shin, J.-G., 1998, "Dynamics of inorganic N.P nutrient and planktonic algae during summer and winter in downstream of the Naktong river", Kor. J. Lim., Vol. 31, No. 1, 67-75.
  6. Choe, S. and Chung, T.W., 1972, "Nutrients and suspended organic particulates in the estuary of Nak-Dong river", J. Oceanolog. Soc. Kor., Vol. 7, No. 1, 1-14.
  7. Chung, I.K., Kang, Y.J., Kwon, O-S. and Seo, J.K., 2000, "The ecology of phytoplankton in the Nakdong estuary", Algae, Vol. 15, No. 2, 99-110.
  8. Chung, M.H. and Youn, S.-H., 2013, "Temporal and spatial variability of phytoplankton communities in the Nakdong river estuary and coastal area, 2011-2012", The Sea, Vol. 18, No. 4, 214- 226. https://doi.org/10.7850/jkso.2013.18.4.214
  9. Domingues, R.B., Barbosa, A. and Galvao, H., 2005, "Nutrients, light and phytoplankton succession in a temperate estuary (the Guadiana, south-western Iberia)", Estuar. Coast. Shelf Sci., Vol. 64, 249-260. https://doi.org/10.1016/j.ecss.2005.02.017
  10. Domingues, R.B., Barbosa, A.B, and Galvao, H.M., 2014, "River damming leads to decreased phytoplankton biomass and disappearance of cyanobacteria blooms", Estuarine, Coastal and Shelf Science, Vol. 136, 129-138. https://doi.org/10.1016/j.ecss.2013.11.012
  11. Humborg, C., Ittekkot, V., Cociasu, A. and Bodungen, B.V., 1997, "Effect of Danube River dam on Black Sea biogeochemistry and ecosystem structure", Nature, 386, 385-388. https://doi.org/10.1038/386385a0
  12. Jang, S.-T. and Kim, K.-C., 2006, "Change of oceanographic environment in the Nakdong Estuary", The Sea, Vol. 11, No. 1, 11-20.
  13. Jennerjahn, T.C. and Mitchell, S.B., 2013, "Pressures, stresses, shocks and trends in estuarine ecosystems-An introduction and synthesis", Estuarine, Coastal and Shelf Science, Vol. 130, 1-8. https://doi.org/10.1016/j.ecss.2013.07.008
  14. Kim, J.G., You, S.-J. and Kwon, J.-N., 1998, "Variations of water quality after construction of Keum river estuary barrage", J. Kor. Fish. Soc., Vol. 31, No. 5, 685-694.
  15. Kim, K.C., Kim, J.J., Kim, Y.E. and Han, K.M., 1996, "Outflow characteristics of Nakdong river plume", J. Kor. Soc. Coastal and Ocean Engineers, Vol. 8. No. 4, 305-313.
  16. Kim, I.-B., 1970, "Fundamental studies of the lower part of the NakTong river for fisheries exploitation", Bull. Kor. Fish. Soc., Vol. 3, No. 1, 65-70.
  17. Kim, S.H., Yoon, I.-K., Song, S.J., Kim, Y.E. and Kwon, O-S., 1996, "Environmental factors and benthic microbial distributions in the sediments of Naktong river estuary", Kor. J. Lim., Vol. 29, No. 3, 205-214.
  18. Kim, W-J. and Lee, H.-J., 1998, "The environmental factors and distribution of microorganisms of Naktong river estuary", Kor. J. Limnol., Vol. 31, No. 1, 25-31.
  19. Kim, Y.-G., Shin, H.-K., Cho, H.-R. and You, S.-J., 1984, "Seasonal variations of water quality in the lower part of the Nagdong river", Bull. Kor. Fish. Soc., Vol. 17, No. 6, 511-522.
  20. Kwon, J.-N., Shim, J.H., Lee, S.Y. and Cho, J.D., 2013, "Effects of meteorological and oceanographic properties on variability of laver production at Nakdong river estuary, south coast of Korea", Kor. J. Fish. Aquat. Sci., Vol. 46, No. 6, 868-877. https://doi.org/10.5657/KFAS.2013.0868
  21. Lee, J.Y., Kwon, J.N. and An, S.M., 2012, "Seasonal variation of nitrogen loads and nitrogen cycling at tidal flat sediments in Nakdong river estuary", The Sea, Vol. 17, No. 2, 120-129. https://doi.org/10.7850/jkso.2012.17.2.120
  22. Liu, M., Xiao, T., Wu, Y., Zhou, F., Huang, H., Bao, S. and Zhang, W., 2012, "Temporal distribution of bacterial community structure in the Changjiang estuary hypoxia area and the adjacent East China Sea", Environ. Res. Lett., Vol. 7, No. 2, 025001. https://doi.org/10.1088/1748-9326/7/2/025001
  23. MOF, 2013, "Guideline to standard methods for the marine environment", Ministry of Government Legislation, p. 516.
  24. Moon, C.-H. and Choi, H.-J., 1991, "Studies on the environmental characteristics and phytoplankton community in the Nakdong river estuary", J. Oceanolog. Soc. Kor., Vol. 26, No. 2, 144-154.
  25. Moon, C.-H. and Kwon, K.-Y., 1994, "Seasonal variations of particulate biogenic silica in the Nakdong river estuary", J. Kor. Soc., Vol. 29, No. 1, 5-16.
  26. Morris, A.W., Bale, A.J. and Howland, R.J.M., 1981, "Nutrient distributions in an estuary: Evidence of chemical precipitation of dissolved silicate and phosphae", Estuar. Coast. Shelf Sci., Vol. 12, 205-216. https://doi.org/10.1016/S0302-3524(81)80097-7
  27. Ning, X., Lin, C., Su, J., Liu, C. and Hao, Q., 2011, "Long-term changes of dissolved oxygen, hypoxia, and the responses of the ecosystems in the East China sea from 1975 to 1995", J. Oceanogr., Vol. 67, 59-75. https://doi.org/10.1007/s10872-011-0006-7
  28. Shin, S.-K., Park, C.-K. and Song, K.-O., 1998, "Evaluation of water quality using principal component analysis in the Nakdong river estuary", J. Kor. Environ. Sci. Soci., Vol. 7, No. 2, 171-176.
  29. Shin, Y.S. and Yoon, B.B., 2011, "Change in taxonomic composition of phytoplankton and environmental factors after construction of dike in Yeongsan river estuary", Kor. J. Environ. Biol., Vol. 29, No. 3, 212-224.
  30. Sin, Y.S., Lee, C.H., Cho, K.A. and Song, E.S., 2005, "Trends of phytoplankton community and water quality and implications for management in estuarine river system", Kor. J. Lim., Vol. 38, No. 2, 160-180.
  31. Turner, R.E., Rabalais, N.N., Swenson, E.M., Kasprzak, M. and Romaire, T., 2005, "Summer hypoxia in the northern gulf of Mexico and its prediction from 1978 to 1995", Mar. Environ. Res., Vol. 59, 65-77. https://doi.org/10.1016/j.marenvres.2003.09.002
  32. Yang, J.-W., Lee, S.-M. and Park, C.-K., 1990a, "Settling characteristics of phosphorus in Nakdong estuary barrage", Bull. Korean Fish. Soc., Vol. 23, No. 3, 185-191.
  33. Yang, J.-W., Song, K.-O. and Lee, S.-M., 1990b, "Release characteristics of phosphorus in Nakdong estuary barrage", Bull. Kor. Fish. Soc., Vol. 23, No. 3, 192-197.
  34. Yang, S.R., Song, H.S., Moon, C.-H., Kwon, K.-Y. and Yang, H.-S., 2001, "Changes in marine environment and primary production due to freshwater input in the Nakdong estuary", Algae, Vol. 16, No. 2, 165-177.
  35. Yoon, I.B., Bae, K.-S. and Kong, D.-S., 1987, "A study on the physiochemical factors and macrozoobenthos community structure in Naktong estuary", Kor. J. Lim. Vol. 20, No. 2, 73-99.
  36. Zhu, Z.-Y., Zhang, J., Wu, Y., Zhang, Y.-Y., Lin, J. and Liu, S.-M., 2011, "Hypoxia off the Chanjiang(Yangtze river) estuary: Oxygen depletion and organic matter decomposition", Mar. Chem., Vol. 125, 108-116. https://doi.org/10.1016/j.marchem.2011.03.005